The author appears to have a specific interpretation in mind, yes, and it doesn't match my understanding from the wet-behind-the-ears me at the time.
However, to be more clear, Apple DOS almost certainly was not part of the "DOS market" that the lawsuit concerned. You would have to care far more than I to resolve the underlying issues. I just know the linked-to text doesn't seem to have the ring of truth.
> DOS meant MS-DOS and its licensed variants such as PC DOS
Because I know that Apple had Apple DOS since 1978, and I thought DOS was a general term in that time period